Weights - stuff “below” axles count?

I’m curious if any experts know - when counting up weights to get totals - can things like the weight of the tires & wheels be subtracted? If GVWR is 10,000 lbs and tires + wheels weigh 400 lbs, can you go to 10,400 as it reads on a CAT scale? I’m thinking the GVWR - or more likely the GAWRs - are based on the bearings and frame anchor points to the suspensions. If true, wouldn’t everything “below” that carry its own weight?

 

Adding any items such as heavier tires, bumpers, heavy skid plates, they all count toward the weight. So add the additional weight those items may have over the stock weight. Example- say your stock tires are 40lbs each but you add tires that weigh 60 pounds each- that is an extra 80 pounds total that is taken away from your towing weight. Make sense?

 

It does, and I use an actual truck scale for my total weight so it’s all included. I’m trying to see if - in the actual engineering of these components - the weights of items below the axle truly count, since the axles do not carry that load...

 

Your GVWR is the max total weight for the vehicle as it sits on a scale. Wheels and tires are all part of it. You cannot subtract anything from that CAT scale weight.

 

Yes it all counts toward the weight.

 

Anything not supported by the springs is considered 'unsprung weight'.

 

GVWR and axle weight ratings are two different things. Honestly if you’re close enough to be trying to game the numbers you’re too close

 

IMHO, extra "sprung" weight should count against payload and GVWR limits (impacting suspension & brakes). Extra "unsprung" weight should only count against GVWR limit (impacting brakes). Having said that, however, I do think the difference between the non-loaded truck weight and the GVWR is approximately the payload limit.

 

Yes, but all of it is counted in the total.

Reducing 'sprung' & 'unsprung' weight will increase a vehicles performance, but the factory GVWR rating will remain unchanged.

 

The OP's question is very simple, and so is the answer. The GVWR is the max that vehicle is rated for when put on a scale. Everything, including unsprung weight and cargo, counts toward GVWR. The reason is because the rating isn't solely based on the weight ratings of the axles. It takes into accound the frame design, braking capability, steering, and everything else.

Short answer: If your truck ever scales at anything over the GVWR you are overweight. You cannot change the GVWR with sumo springs, airbags, or new leaf springs. Period.

 

Wasn’t disagreeing just clarifying. Reducing unsprung weight is always beneficial no matter what type of vehicle is being operated.